1. Field of the Invention
The present invention relates in general to a system and method in which a directional tap detection algorithm and a tri-axis accelerometer extend the number of unique buttonless inputs available for small mobile devices like cell phones and MP3 players. The algorithm analyzes acceleration data from the single accelerometer to detect the direction (X+, X−, Y+, Y−, Z+, Z−) and number (single or double) of taps, yielding 12 unique inputs.
2. Description of the Background Art
Mobile devices are getting smaller and smaller for portability these days. The reduction in size limits the space available for input devices (such as buttons and keypads). Many researchers have been studying gesture recognition to remove traditional input devices. In certain environments, a simple motion can be a more effective input. The advent of MEMS (Micro-Electro-Mechanical System) technology dramatically reduced the size of accelerometers which can detect an object's motion. Tapping is a very simple motion. It is intuitive and not necessary to learn. If tapping a device anywhere on its surface could be used to control the device, then it would be a unique input methodology.
Rudimentary tap detection typically allows for two distinct input commands. These are often referred to as tap and double tap. However, there is a need for proving a multiplicity of tap commands in the aforementioned small mobile devices.